Introduction
Network Assessment Goals
Positioning
Phase 1 – Discovery
Phase 2 – Modelling
Phase 3 – Traffic Simulation
Phase 4 – Recommendations
Recap
Network Impact
User Experience
How does real-time communication (RTC) affect
your network?
Network as a foundation of success.
How does your network affect real-time
communication
Lync deployments can fail because of network
issues.
The technology is only as good as the last call.
Proactive
Reactive
What are your plans for voice and video?
Is your customer having quality issues?
Is your network ready for RTC/UC?
Have you considered RTC/UC when planning and
building your network?
What are your expectations on usage?
Network Assessment is an offering that provides an application-centric
evaluation to pinpoint problems that could affect your future Microsoft
Unified Communications solution.
Discovery session
Usage modeling
Traffic simulation
Recommendations
Understand what
network environment
exists
Model proposed
bandwidth usage
with user profiles and
usage patterns
Use a UC traffic
simulator to apply
real traffic to a
production network
and monitor factors
that affect traffic
quality, such as delay,
jitter, and packet loss
Analyze factors that
affect quality and
produce a full report
with recommendations
Proactive
approach
Early discovery
Assess readiness
Layer 7 analysis
Recommendations
on Lync
deployment
Measure actual
performance
Validates an
enterprise’s readiness
for real-time
communications (RTC)
Provides a quantitative
assessment of current
infrastructure metrics
that affect RTC
Reduces deployment
risk
Highlights areas that
might have an impact
on RTC readiness
Protects customer’s
investment in RTC
Promotes the best
possible user
experience
Should be part of every Enterprise Voice deployment
A large percentage of voice support calls are related to
network impairments
Can be conducted when:
Lync is introduced
New workloads are introduced
New user populations are enabled for Lync
QoS is being introduced/adopted
Discover equipment
Upgrade network
Configure network
Evaluate
configuration
Troubleshoot
network issues
Validate existing
concerns
Poor UC
user experience
Increased number of
help desk tickets
Frustration and poor
perception of the
product’s ability
Saturated networks
can affect other line of
business (LOB)
applications
Poor return on UC
investment
Reduced productivity
and collaboration
Discovery objective
Come up with data that can be used to depict the factual state of
the network.
Discovery goals
Uncover current or future potential sources of network impairments.
Confirm simulation probe placement choice.
Ensure information is collected for calibration of usage models.
Understand the customer’s network
Collect data for proper scoping and scaling
Help build a usage model for the customer
Identify risk elements that could affect Lync deployment
Eliminate last minute surprises, identify overlooked areas
Bring different groups together, probably for the first time
(Networking, Lync Voice)
Network overview
Site details
WAN tech and link speeds
LAN/Wi-Fi tech in the enterprise
Quality of Service strategies
PSTN setups
Existing SLAs on WAN
Historical metrics
Usage profiles
Application sharing
Conferencing in the enterprise
RTC applications
(IM/presence/voice/video)
Legacy voice architecture
PSTN usage
Network Assessment
Discovery phase... information collection
Network Assessment
QoS policies
Network
topology
Is QoS in place?
If so, what type of QoS?
Is there WAN QoS?
Are there WAN SLAs?
Max percentage of links that
can be reserved for UC
traffic?
Network
utilization kevels
Regional WAN
bottlenecks
How many sites do you
have?
Describe Layer 2 and Layer 3
resiliency.
Do you log current
utilization levels?
Firewall
architecture
Are there multiple WAN
providers? Regional
bottlenecks?
Discuss your firewall
architecture – for example,
internal and external
firewalls.
Objective: Provide data on usage patterns and bandwidth
consumption (average and peak busy hour, RTC usage) of various
links over a period of time.
Potential risk: Not knowing the utilization metrics could potentially
overload the links, causing serious congestion and drops.
Basic tasks
Define sites
Define WAN link bandwidth for each site
Define bandwidth available for RTC traffic
Define Internet link bandwidth (for central sites)
Create/update personas
Define number of users per site
Analyze results
Download link:
http://www.microsoft.com/enus/download/details.aspx?id=19011
Lync bandwidth calculator consists two documents:
Excel sheet. The calculator tool, valid for Lync 2010 and Lync 2013.
User guide. Word document that explains how to use the tool.
Simulate real traffic to anticipate real network issues prior to the
deployment of Lync.
Simulate traffic for an extended period of time—1 week is a
good RTC/UC starting point.
Simulation should happen under normal network load.
Simulate Lync traffic flows, P2P, conferencing, PSTN, and so on.
Only under stress will the network reveal how it actually
operates.
Without congestion there’s no buffering, so no jitter and no
packet loss.
Essentially, we need to simulate Lync traffic because no real Lync
traffic exists yet in the network !
26
For 1 week, 24 hours a day
Need to have enough data for analysis because ”things may be happening, but not that often.”
Need to see if there are any patterns.
It’s just Lync-like traffic, but it is real and there can
be a lot of it
Can harm the network!
QoS settings (Differentiated Services Code Point, or DSCP) may be
applied
Should be discussed with the customer.
27
Guidance on where to upgrade WAN links if needed
Guidance on where to improve network with respect to:
Latency
Jitter
Packet loss
Provide input into the Lync design process
Limit number of concurrent calls
Limit workloads (for example, audio only)
Deploy localized infrastructure
Customer assumed QoS on all Multiprotocol Label Switching (MPLS)
links
Network assessment revealed
MPLS provider dropped QoS markings on specific MPLS links
20% not able to send QoS markings
One site not able to send or receive QoS markings
Priority queue was never used because of QoS misconfiguration
One-way QoS provided inconsistent user experience
Discovery session
Usage modeling
Traffic simulation
Recommendations
Understand what
network environment
exists
Model proposed
bandwidth usage
with user profiles and
usage patterns
Use a UC traffic
simulator to apply
real traffic to a
production network
and monitor factors
that affect traffic
quality, such as delay,
jitter, and packet loss
Analyze factors that
affect quality and
produce a full report
with recommendations
36